In electrical installations, what is the purpose of measuring impedance?

Measuring impedance is crucial for ensuring correct grounding and fault protection in electrical installations. Impedance reflects the total opposition that a circuit presents to the flow of alternating current (AC), combining both resistance and reactance. When grounding systems and protective devices like circuit breakers are in place, accurate impedance measurements help confirm that they will function effectively under fault conditions.

In an electrical system, proper grounding minimizes shock hazards and equipment damage by providing a safe path for fault currents. If the impedance of the grounding path is too high, it may not allow sufficient fault current to flow, potentially failing to trip protective devices in the event of a fault. This could lead to unsafe conditions, equipment failure, or even fire hazards.

While efficient energy usage, assessing circuit length, and verifying phase sequence are important aspects of electrical installations, they are not directly related to the specific purpose of measuring impedance. Thus, ensuring correct grounding and fault protection is the primary objective when measuring impedance in electrical systems.